Polymer Ammunition and Cartridge Primer Insert

ABSTRACT

The present invention provides a polymer ammunition cartridge having a primer insert having: a top surface; a bottom surface opposite the top surface; a coupling element that extends from the bottom surface, wherein the coupling element comprises an interior surface and an exterior surface, wherein the interior surface comprises: a transition region that transitions from the bottom surface to a second segment wherein the transition region has a radius of from 0.02 to 0.2; a first segment extending from the second segment and terminates at a tip, wherein the first segment has a first segment distance from 0.02 to 0.18 inches and the second segment has a second segment distance from 0.02 to 0.18 inches, wherein the second segment has a second segment angle from +3 to −3 degrees relative to the first segment angle and the first segment has a first segment angle from +6 to −6 degrees from perpendicular to the top surface; a primer recess in the top surface that extends toward the bottom surface; a primer flash aperture positioned in the primer recess through the bottom surface; and a flash aperture groove in the primer recess and positioned around the primer flash aperture and adapted to receive a polymer overmolding through the primer flash aperture.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of co-pending U.S. patentapplication Ser. No. 16/111,692 file on Aug. 24, 2018, which is aContinuation application of U.S. patent application Ser. No. 15/911,544filed on Mar. 5, 2018 now U.S. Pat. No. 10,352,664 issued Jul. 16, 2019,which is a continuation of U.S. patent application Ser. No. 15/406,844filed on Jan. 16, 2017 now U.S. Pat. No. 9,933,241 issued Apr. 3, 2018,which is a continuation of U.S. patent application Ser. No. 14/011,202filed on Aug. 27, 2013 now U.S. Pat. No. 9,546,849 issued Jan. 17, 2017,which is a division of U.S. patent application Ser. No. 13/292,843 filedon Nov. 9, 2011 now U.S. Pat. No. 8,561,543 issued Oct. 13, 2013, whichclaims the benefit of U.S. Provisional Patent Application Ser. No.61/456,664, filed Nov. 10, 2010, the contents of each are herebyincorporated by reference in their entirety.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to the field of ammunition,specifically to compositions of matter and methods of making and usingpolymeric ammunition cartridge primer inserts.

STATEMENT OF FEDERALLY FUNDED RESEARCH

None.

INCORPORATION-BY-REFERENCE OF MATERIALS FILED ON COMPACT DISC

None.

BACKGROUND OF THE INVENTION

Without limiting the scope of the invention, its background is describedin connection with lightweight polymer cartridge casing ammunition.Conventional ammunition cartridge casings for rifles and machine guns,as well as larger caliber weapons, are made from brass, which is heavy,expensive, and potentially hazardous. There exists a need for anaffordable lighter weight replacement for brass ammunition cartridgecases that can increase mission performance and operationalcapabilities. Lightweight polymer cartridge casing ammunition must meetthe reliability and performance standards of existing fielded ammunitionand be interchangeable with brass cartridge casing ammunition inexisting weaponry. Reliable cartridge casings manufacture requiresuniformity (e.g., bullet seating, bullet-to-casing fit, casing strength,etc.) from one cartridge to the next in order to obtain consistentpressures within the casing during firing prior to bullet and casingseparation to create uniformed ballistic performance. Plastic cartridgecasings have been known for many years but have failed to providesatisfactory ammunition that could be produced in commercial quantitieswith sufficient safety, ballistic, handling characteristics, and survivephysical and natural conditions to which it will be exposed during theammunition's intended life cycle; however, these characteristics havenot been achieved.

For example, U.S. patent application Ser. No. 11/160,682 discloses abase for a cartridge casing body for an ammunition article, the basehaving an ignition device; an attachment device at one end thereof, theattachment device being adapted to the base to a cartridge casing body;wherein the base is made from plastic, ceramic, or a composite material.

U.S. Pat. No. 7,610,858 discloses an ammunition cartridge assembled froma substantially cylindrical polymeric cartridge casing body defining acasing headspace with an open projectile-end and an end opposing theprojectile-end, wherein the casing body has a substantially cylindricalinjection molded polymeric bullet-end component with opposing first andsecond ends, the first end of which is the projectile-end of the casingbody and the second end has a male or female coupling element; and acylindrical polymeric middle body component with opposing first andsecond ends, wherein the first end has a coupling element that is a matefor the projectile-end coupling element and joins the first end of themiddle body component to the second end of the bullet-end component, andthe second end is the end of the casing body opposite the projectile endand has a male or female coupling element; and a cylindrical cartridgecasing head-end component with an essentially closed base end with aprimer hole opposite an open end with a coupling element that is a matefor the coupling element on the second end of the middle body and joinsthe second end of the middle body component to the open end of thehead-end component; wherein the middle body component is formed from amaterial more ductile than the material head-end component is formedfrom but equal or less ductile than the material the bullet-endcomponent is formed from. Methods for assembling ammunition cartridgesand ammunition cartridges having the headspace length larger than thecorresponding headspace length of the chamber of the intended weaponmeasured at the same basic diameter for the cartridge casing withoutbeing so large as to jam the weapon or otherwise interfere with itsaction are also disclosed.

Shortcomings of the known methods of producing plastic or substantiallyplastic ammunition include the possibility of the projectile beingpushed into the cartridge casing, the bullet pull being too light suchthat the bullet can fall out, the bullet pull being too insufficient tocreate sufficient chamber pressure, the bullet pull not being uniformfrom round to round, and portions of the cartridge casing breaking offupon firing causing the weapon to jam or damage or danger whensubsequent rounds are fired or when the casing portions themselvesbecome projectiles. To overcome the above shortcomings, improvements incartridge case design and performance polymer materials are needed.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a primer insert for a polymer ammunitioncartridge comprising: a top surface; a bottom surface opposite the topsurface; a coupling element that extends from the bottom surface,wherein the coupling element comprises an interior surface and anexterior surface, wherein the interior surface comprises: a transitionregion that transitions from the bottom surface to a second segmentwherein the transition region has a radius of from 0.02 to 0.2; a firstsegment extending from the second segment and terminates at a tip,wherein the first segment has a first segment distance from 0.02 to 0.18inches and the second segment has a second segment distance from 0.02 to0.18 inches, wherein the second segment has a second segment angle from+3 to −3 degrees relative to the first segment angle and the firstsegment has a first segment angle from +6 to −6 degrees fromperpendicular to the top surface; a primer recess in the top surfacethat extends toward the bottom surface; a primer flash aperturepositioned in the primer recess through the bottom surface; and a flashaperture groove in the primer recess and positioned around the primerflash aperture and adapted to receive a polymer overmolding through theprimer flash aperture. The primer insert has an insert height thatextends from the top surface to the tip, wherein the insert height isbetween 0.05 and 0.75 inches, the insert height is about 0.36 inches,the insert height is about 0.38 inches or the insert height is about 0.4inches. The transition region comprises one or more straight segments,one or more curved segments or a combination of one or more straightsegments and one or more curved segments. The first segment has a firstsegment distance is about 0.08 inches, the second segment has a secondsegment distance is about 0.08 inches and the transition region isconcave with a radius of about 0.04. The second segment has a secondsegment angle is about 1 degrees and the first segment has a firstsegment is about 3 degrees. The second segment has a second segmentangle is about 3 degrees and the first segment has a first segment isabout 0 degrees. The primer insert of claim 3, further comprising aninsert height that extends from the top surface to the tip, wherein theinsert height is about 0.34 inches, about 0.36 inches, or about 0.38inches. The first segment has a first segment distance is about 0.079inches, the second segment has a second segment distance is about 0.083inches and the transition region is concave with a radius of about 0.04.The second segment has a second segment angle is about 1 degrees and thefirst segment has a first segment is about 3 degrees. The second segmenthas a second segment angle is about 3 degrees and the first segment hasa first segment is about 0 degrees. The primer insert further comprisingan insert height that extends from the top surface to the tip, whereinthe insert height is about 0.34 inches, about 0.36 inches or about 0.38inches. The first segment has a first segment distance is about 0.076inches, the second segment has a second segment distance is about 0.086inches and the transition region is concave with a radius of about 0.04.The second segment has a second segment angle is about 1 degrees and thefirst segment has a first segment is about 3 degrees. The second segmenthas a second segment angle is about 3 degrees and the first segment hasa first segment is about 0 degrees. The primer insert further comprisingan insert height that extends from the top surface to the tip, whereinthe insert height is about 0.034, 0.36 inches, 0.38 inches, or 0.40inches. The first segment has a first segment distance is about 0.082inches, the second segment has a second segment distance is about 0.08inches and the transition region is concave with a radius of about 0.04.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

For a More Complete Understanding of the Features and Advantages of thePresent Invention, Reference is Now Made to the Detailed Description ofthe Invention Along with the Accompanying Figures and in which:

FIG. 1 depicts an exploded view of the polymeric cartridge casing;

FIG. 2 depicts an elevation view of one embodiment of the primer insertof the present invention;

FIG. 3 depicts a side, cross-sectional view of a polymeric cartridgecase according to one embodiment of the present invention;

FIG. 4 depicts a side, cross-sectional view of a portion of thepolymeric cartridge case according to one embodiment of the presentinvention;

FIG. 5 depicts a side, cross-sectional view of a primer insert accordingto one embodiment of the present invention;

FIG. 6 depicts a side, cross-sectional view of a portion of thepolymeric cartridge case displaying ribs according to one embodiment ofthe present invention;

FIG. 7 depicts a side, cross-sectional view of a polymeric cartridgecase having a diffuser according to one embodiment of the presentinvention;

FIG. 8 depicts a side, cross-sectional view of a portion of thepolymeric cartridge case having a diffuser according to one embodimentof the present invention; and

FIGS. 9a-9h depict diffuser according to a different embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

While the making and using of various embodiments of the presentinvention are discussed in detail below, it should be appreciated thatthe present invention provides many applicable inventive concepts thatcan be embodied in a wide variety of specific contexts. The specificembodiments discussed herein are merely illustrative of specific ways tomake and use the invention and do not delimit the scope of theinvention.

To facilitate the understanding of this invention, a number of terms aredefined below. Terms defined herein have meanings as commonly understoodby a person of ordinary skill in the areas relevant to the presentinvention. Terms such as “a”, “an” and “the” are not intended to referto only a singular entity, but include the general class of which aspecific example may be used for illustration. The terminology herein isused to describe specific embodiments of the invention, but their usagedoes not delimit the invention, except as outlined in the claims.

Reliable cartridge manufacture requires uniformity from one cartridge tothe next in order to obtain consistent ballistic performance. Amongother considerations, proper bullet seating and bullet-to-casing fit isrequired. In this manner, a desired pressure develops within the casingduring firing prior to bullet and casing separation. Historically,bullets employ a cannelure, which is a slight annular depression formedin a surface of the bullet at a location determined to be the optimalseating depth for the bullet. In this manner, a visual inspection of acartridge could determine whether or not the bullet is seated at theproper depth. Once the bullet is inserted into the casing to the properdepth, one of two standard procedures is incorporated to lock the bulletin its proper location. One method is the crimping of the entire end ofthe casing into the cannelure. A second method does not crimp the casingend; rather the bullet is pressure fitted into the casing.

The polymeric ammunition cartridges of the present invention are of acaliber typically carried by soldiers in combat for use in their combatweapons. The present invention is not limited to the described caliberand is believed to be applicable to other calibers as well. Thisincludes various small and medium caliber munitions, including 5.56 mm,7.62 mm, 12.7 mm and .50 caliber ammunition cartridges, as well asmedium/small caliber ammunition such as 380 caliber, 308 caliber, 38caliber, 9 mm, 10 mm, 20 mm, 25 mm, 30 mm, 40 mm, 45 caliber and thelike. The cartridges, therefore, are of a caliber between about .05 andabout 5 inches. Thus, the present invention is also applicable to thesporting goods industry for use by hunters and target shooters.

FIG. 1 depicts an exploded view of the polymeric ammunition 10. Apolymeric cartridge 12 suitable for use with high velocity rifles isshown manufactured with a polymeric middle body component 28 having apolymeric nose 18. The polymeric middle body component 28 includes anovermolded primer insert 32 and forms a propellant chamber 14. Theinsert 32 also includes a primer recess (not shown) formed therein forinsertion of the primer (not shown). The polymeric nose 18 has ashoulder 24 connected to a chamber neck 26 terminating in a projectileaperture 16 which accepts a bullet 56 therein.

FIG. 2 depicts an elevation view of one embodiment of the primer insert32 of the present invention. The primer insert 32 includes a couplingelement 30 extending from a bottom surface (not shown) and tapers to asmaller diameter at the tip 44. When the primer insert 32 is overmoldedwith the middle body component (not shown) over the substantiallycylindrical coupling element 30 and the tip 44 to form a physicalinterlock between primer insert 32 and middle body component (notshown). The primer insert 32 also has a flange 46 at one end and aprimer recess (not shown) formed therein for insertion of a primer (notshown).

FIG. 3 depicts a side, cross-sectional view of a polymeric cartridgecase according to one embodiment of the present invention. Theammunition cartridge 10 includes a polymer cartridge 12 overmolding aprimer insert 32, a polymeric nose 18, a propellant/powder chamber 14and a projectile aperture 16. The polymeric nose 18 extending fromprojectile aperture 16 toward the nose joint 20 which are separated by aneck 26 and a shoulder 24. The nose joint 20 may be configured invarious designs that allow the joining of the polymeric nose 18 to themiddle body component 28. For example, the joint 20 may be a butt joint,a bevel lap splice joint, a half lap joint, a lap joint, a square joint,a single bevel joint, double bevel joint, single J joint, double Jjoint, single v joint, double v joint, single U joint, double U joint,flange joint, tee joint, flare joint, edge joint, rabbit joint, dado andany other joint. In addition, the joint type may be modified to allow agap at regions in the joint. For example, a dado joint may be formedwhere the fit is not square allowing gaps to form at the corner of thedado. Similarly, a compound joint may be used, e.g., rabbit jointtransitioning to a butt joint transitioning to a bevel joint (modifiedto have a gap in the fit) transitioning to a butt joint and ending in alap joint or rabbit joint. In addition the angle of the joint need notbe at 90 and 180 degrees. The joint angle may be at any angle from 0-180degrees and may vary along the joint. For instance the joint may startat a 0 degree move to a +45 degree angle transition to a −40 degreeangle and conclude by tapering at a 10 degree angle. The polymeric nose18 typically has a wall thickness between about 0.003 and about 0.200inches and preferably between about 0.005 and more preferably betweenabout 0.150 inches about 0.010 and about 0.050 inches.

The middle body component 28 is formed by molding a case joint 19 at oneend and overmolding the primer insert 32 at the other. A couplingelement 30 extending from a bottom surface 34 that is opposite a topsurface 36. The middle body component 28 overmolds the coupling element30 of the insert 32. The coupling element 30, as shown, is configured asa male element, however, all combinations of male and femaleconfigurations are acceptable for coupling elements 30. Located in thetop surface 36 of the primer insert is a primer recess 38 that extendstoward the bottom surface 34. A primer flash aperture 40 is located inthe primer recess 38 and extends through the bottom surface 34 into theinterior of the middle body component 28 to form a powder chamber 14.The coupling end 22 extends the polymer through the primer flashaperture 40 to form an aperture coating 42 while retaining a passagefrom the top surface 36 through the bottom surface 34 and into thepowder chamber 14 to provide support, communication and protection aboutthe primer flash aperture 40. The middle body component 28 extendsthrough the flash aperture 40 into the primer recess 38 and into aprimer recess groove 39. The middle body component 28 typically has awall thickness between about 0.002 and about 0.400 inches and between0.003 and about 0.200 inches more preferably between about 0.005 andmore preferably between about 0.150 inches about 0.010 and about 0.050inches. The projectile aperture 16, the middle body 28 and theovermolded bottom surface 34 define the interior of a powder/propellantchamber 14 in which the powder charge (not shown) is contained. Theinterior volume of powder/propellant chamber 14 may be varied to providethe desired volume of powder/propellant to achieve the desired goal,e.g., fps, pressure, etc. Any powder/propellant known to the skilledartisan can be used. Generally, either a particulate or consolidatedpropellant is used. The primer insert 32 also has a flange 46 and aprimer recess 38 formed therein for ease of insertion of the primer (notshown). The primer recess 38 is sized to receive a primer (not shown) inan interference fit during assembly. A diffuser (not shown) may beplaced between the primer (not shown) and the bottom of the primerrecess 38. The diffuser may be of any diameter, thickness and material.A primer flash hole 40 communicates through the bottom surface 34 ofprimer insert 32 into the powder chamber 14 so that upon detonation ofthe primer (not shown), the powder in the powder chamber 14 will beignited. The projectile (not shown) is held in place within the neck 26at forward the projectile aperture 16 by an interference fit, mechanicalcrimping, adhesive, bonding welding, or etc. to increase the bullet pullforce.

In another embodiment, the polymer casing (not shown) includes anopen-ended middle body component (not shown) that terminates in aprojectile aperture (not shown) that fits a projectile (not shown)directly and does not need a nose (not shown) to reduce the diameterfrom the cartridge (not shown) diameter to the projectile aperture (notshown) diameter. The middle body component (not shown) extends from aprojectile aperture (not shown) to coupling element (not shown). Thebullet (not shown) may be inserted into the projectile aperture 16following the insertion of the diffuser (not shown) and primer (notshown) into the primer recess (not shown) and the addition of thepropellant (not shown) to the propellant/powder chamber 14. Theprojectile (not shown) can be fitted into the projectile aperture 16prior to welding or bonding together using solvent, adhesive,spin-welding, vibration-welding, ultrasonic-welding or laser-weldingtechniques. The welding or bonding increases the joint strength betweenthe polymer cartridge 12 and the projectile (not shown) to produce thedesired projectile (not shown) retention (i.e., bullet pull). Anoptional first and/or second annular groove (cannelures) may be providedin the neck 26 in the interlock surface of the male coupling element toprovide a snap-fit between the two components. The cannelures (notshown) formed in a surface of the bullet (not shown) at a locationdetermined to be the optimal seating depth for the bullet (not shown).Once the bullet (not shown) is inserted into the polymeric nose 18 atthe proper depth the bullet (not shown) is locked into the properlocation. Another embodiment includes positioning the bullet (not shown)into the polymeric nose 18 and crimping the neck 26 into the cannelures.The polymeric nose 18 and middle body component 28 can also be welded orbonded together using solvent, adhesive, spin-welding,vibration-welding, ultrasonic-welding or laser-welding techniques at thenose joint 20 and the case joint 19. The welding or bonding increasesthe joint strength so the casing can be extracted from the hot guncasing after firing at the cook-off temperature without failure of thepolymer cartridge 12.

FIG. 4 depicts a side, cross-sectional view of a portion of thepolymeric cartridge case according to one embodiment of the presentinvention shown in FIG. 3. FIG. 4 shows a portion of a polymer casing 12showing a powder chamber 14 and the primer insert 32. The primer insert32 includes a coupling element 30 extending from a bottom surface 34that is opposite a top surface 36. Located in the top surface 36 is aprimer recess 38 that extends toward the bottom surface 34. A primerflash aperture 40 is located in the primer recess 38 and extends throughthe bottom surface 34 into the powder chamber 14. The coupling end 22extends the polymer over the coupling element 30 and through the primerflash aperture 40 to form an aperture coating 42 that retains thepassage from the top surface 36 through the bottom surface 34 and intothe powder chamber 14 while providing support and protection about theprimer flash aperture 40. When contacted the middle body component 28interlocks with the coupling element 30 that extends with a taper to asmaller diameter at the tip 44 and forms a physical interlock betweenthe primer insert 32 and middle body component 28. The middle bodycomponent 28 extends through the flash aperture 40 into the primerrecess 38 into a primer recess groove 39 located around the flashaperture 40 in the primer recess 38. Coupling end 22 is shown as afemale element, but may also be configured as a male element inalternate embodiments of the invention. A diffuser maybe placed in theprimer recess against the primer recess groove 39 and the primer (notshown).

FIG. 5 depicts a side, cross-sectional view of a primer insert 32according to one embodiment of the present invention. The primer insert32 includes a coupling element 30 extending from a bottom surface 34that is opposite a top surface 36 and terminate at a tip 44. The tip 44includes an end 502 separated from a first point 504 by a first segment506. The first segment 506 has a first segment angle and a first segmentlength. A second segment 508 extends from the first point 504 to asecond point 510. The second segment 508 has a second segment angle andsecond segment length. A transition segment 512 extends from the secondpoint 510 to a third point 514. The transition segment 512 transitionsfrom a vertical position to a horizontal position. The transitionsegment 512 may be one or more straight segments, curved segments,radius or other free formed segments, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 65, 70, 75,80, 85, 90, 95 or more until it approaches or can be functionally viewedas a curves surface to achieve a radius from 0.02-0.2. A third segment516 extends from the third point 514 to a fourth point 518 to form athird segment length with a third segment angle of 80 and 100 degreesrelative to the first segment angle. In other embodiments, the firstsegment 506, the second segment 508, third segment 516 may be subdivideinto multiple segments (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31,32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49,50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 65, 70, 75, 80, 85, 90, 95or more) with each having independent angles and provide the samefunction without departing from the scope of the instant invention.

The first segment 506 may have a first segment angle between ±6 degreesfrom perpendicular to the top surface 36 and a first segment distance of0.10±0.08. The first segment 506 length may be 0.02, 0.03, 0.04, 0.05,0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17,0.18, 0.19, 0.2 and variable increment of 0.001-0.010. Similarly thefirst segment 506 may have an angle of −6, −5.75, −5.5, −5.25, −5.0,−4.75, −4.5, −4.25, −3.75, −3.5, −3.25, −2.75, −2.5, −2.25, −1.75, −1.5,−1.25, −0.75, −0.5, −0.25, −0.05, 0, 6, 5.75, 5.5, 5.25, 5.0, 4.75, 4.5,4.25, 3.75, 3.5, 3.25, 2.75, 2.5, 2.25, 1.75, 1.5, 1.25, 0.75, 0.5,0.25, 0.05, and incremental variations thereof degrees fromperpendicular to the top surface 36. Individual examples include a firstsegment 506 length of 0.06, 0.068, 0.07, 0.079, 0.08 0.066, 0.09, 0.095,0.10, or 0.075.

The second segment 508 may have an angle between −3 and 3 degreesrelative to the first segment angle and a first segment distance of0.10±0.08. Individual examples include a second segment 508 length of0.07, 0.073, 0.075, 0.08, 0.083, 0.09, 0.072, 0.1, 0.102, 0.11, 0.116,or 0.12.

The transition segment 512 may be a transition equivalent to a radius of0.02 to 0.2, e.g., 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10,0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2 and variableincrement of 0.001-0.010. Individual examples include a transitionsegment 512 radius of 0.05, 0.04, or 0.14.

The Third Segment 516 May have an Angle Between 80-100 Degrees Relativeto the First Segment Angle and a Third Segment Distance of Necessary toExtend to the Flash Aperture 40.

In combination, the primer insert 32 may have a height from top surface36 to tip 44 of about 0.375 with a first segment 506 length of about0.068 at about 0 degrees, a second segment 508 length of about 0.073 atabout 3 degrees with a transition segment 512 having a radius of about0.05. In combination, the primer insert 32 may have a height from topsurface 36 to tip 44 of about 0.38 with a first segment 506 length ofabout 0.07 at about 0 degrees, a second segment 508 length of about 0.07at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.4 with a first segment 506 length ofabout 0.07 at about 0 degrees, a second segment 508 length of about 0.07at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.35 with a first segment 506 lengthof about 0.06 at about 0 degrees, a second segment 508 length of about0.07 at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.375 with a first segment 506 lengthof about 0.068 at about 2 degrees, a second segment 508 length of about0.073 at about 3 degrees with a transition segment 512 having a radiusof about 0.05. In combination, the primer insert 32 may have a heightfrom top surface 36 to tip 44 of about 0.38 with a first segment 506length of about 0.07 at about 2 degrees, a second segment 508 length ofabout 0.07 at about 3 degrees with a transition segment 512 having aradius of about 0.05. In combination, the primer insert 32 may have aheight from top surface 36 to tip 44 of about 0.4 with a first segment506 length of about 0.07 at about 2 degrees, a second segment 508 lengthof about 0.07 at about 3 degrees with a transition segment 512 having aradius of about 0.05. In combination, the primer insert 32 may have aheight from top surface 36 to tip 44 of about 0.35 with a first segment506 length of about 0.06 at about 2 degrees, a second segment 508 lengthof about 0.07 at about 3 degrees with a transition segment 512 having aradius of about 0.05. In combination, the primer insert 32 may have aheight from top surface 36 to tip 44 of about 0.375 with a first segment506 length of about 0.068 at about 0 degrees, a second segment 508length of about 0.073 at about 5 degrees with a transition segment 512having a radius of about 0.05. In combination, the primer insert 32 mayhave a height from top surface 36 to tip 44 of about 0.38 with a firstsegment 506 length of about 0.07 at about 0 degrees, a second segment508 length of about 0.07 at about 5 degrees with a transition segment512 having a radius of about 0.05. In combination, the primer insert 32may have a height from top surface 36 to tip 44 of about 0.4 with afirst segment 506 length of about 0.07 at about 0 degrees, a secondsegment 508 length of about 0.07 at about 5 degrees with a transitionsegment 512 having a radius of about 0.05. In combination, the primerinsert 32 may have a height from top surface 36 to tip 44 of about 0.35with a first segment 506 length of about 0.06 at about 0 degrees, asecond segment 508 length of about 0.07 at about 5 degrees with atransition segment 512 having a radius of about 0.05.

In combination, the primer insert 32 may have a height from top surface36 to tip 44 of about 0.360 with a first segment 506 length of about0.079 at about 0 degrees, a second segment 508 length of about 0.083 atabout 3 degrees with a transition segment 512 having a radius of about0.04. In combination, the primer insert 32 may have a height from topsurface 36 to tip 44 of about 0.40 with a first segment 506 length ofabout 0.08 at about 0 degrees, a second segment 508 length of about 0.08at about 3 degrees with a transition segment 512 having a radius ofabout 0.04. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.40 with a first segment 506 lengthof about 0.08 at about 2 degrees, a second segment 508 length of about0.08 at about 3 degrees with a transition segment 512 having a radius ofabout 0.04. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.40 with a first segment 506 lengthof about 0.08 at about 0 degrees, a second segment 508 length of about0.08 at about 5 degrees with a transition segment 512 having a radius ofabout 0.04. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.40 with a first segment 506 lengthof about 0.08 at about 2 degrees, a second segment 508 length of about0.08 at about 6 degrees with a transition segment 512 having a radius ofabout 0.04. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.350 with a first segment 506 lengthof about 0.07 at about 0 degrees, a second segment 508 length of about0.085 at about 3 degrees with a transition segment 512 having a radiusof about 0.04. In combination, the primer insert 32 may have a heightfrom top surface 36 to tip 44 of about 0.350 with a first segment 506length of about 0.07 at about 2 degrees, a second segment 508 length ofabout 0.085 at about 3 degrees with a transition segment 512 having aradius of about 0.04. In combination, the primer insert 32 may have aheight from top surface 36 to tip 44 of about 0.350 with a first segment506 length of about 0.07 at about 0 degrees, a second segment 508 lengthof about 0.085 at about 5 degrees with a transition segment 512 having aradius of about 0.04. In combination, the primer insert 32 may have aheight from top surface 36 to tip 44 of about 0.350 with a first segment506 length of about 0.07 at about 2 degrees, a second segment 508 lengthof about 0.085 at about 6 degrees with a transition segment 512 having aradius of about 0.04.

In combination, the primer insert 32 may have a height from top surface36 to tip 44 of about 0.375 with a first segment 506 length of about0.066 at about 0 degrees, a second segment 508 length of about 0.072 atabout 3 degrees with a transition segment 512 having a radius of about0.05. In combination, the primer insert 32 may have a height from topsurface 36 to tip 44 of about 0.37 with a first segment 506 length ofabout 0.06 at about 0 degrees, a second segment 508 length of about 0.07at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.37 with a first segment 506 lengthof about 0.06 at about 2 degrees, a second segment 508 length of about0.07 at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.37 with a first segment 506 lengthof about 0.06 at about 0 degrees, a second segment 508 length of about0.07 at about 5 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.37 with a first segment 506 lengthof about 0.06 at about 2 degrees, a second segment 508 length of about0.07 at about 6 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.38 with a first segment 506 lengthof about 0.07 at about 0 degrees, a second segment 508 length of about0.07 at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.38 with a first segment 506 lengthof about 0.07 at about 2 degrees, a second segment 508 length of about0.07 at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.38 with a first segment 506 lengthof about 0.07 at about 0 degrees, a second segment 508 length of about0.07 at about 5 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.38 with a first segment 506 lengthof about 0.07 at about 2 degrees, a second segment 508 length of about0.07 at about 6 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.3 with a first segment 506 length ofabout 0.07 at about 0 degrees, a second segment 508 length of about 0.07at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.3 with a first segment 506 length ofabout 0.07 at about 2 degrees, a second segment 508 length of about 0.07at about 3 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.3 with a first segment 506 length ofabout 0.07 at about 0 degrees, a second segment 508 length of about 0.07at about 5 degrees with a transition segment 512 having a radius ofabout 0.05. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.3 with a first segment 506 length ofabout 0.07 at about 2 degrees, a second segment 508 length of about 0.07at about 6 degrees with a transition segment 512 having a radius ofabout 0.05.

In combination, the primer insert 32 may have a height from top surface36 to tip 44 of about 0.645 with a first segment 506 length of about0.095 at about 0 degrees, a second segment 508 length of about 0.102 atabout 3 degrees with a transition segment 512 having a radius of about0.14. In combination, the primer insert 32 may have a height from topsurface 36 to tip 44 of about 0.6 with a first segment 506 length ofabout 0.1 at about 0 degrees, a second segment 508 length of about 0.1at about 3 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.6 with a first segment 506 length ofabout 0.1 at about 2 degrees, a second segment 508 length of about 0.1at about 3 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.6 with a first segment 506 length ofabout 0.1 at about 0 degrees, a second segment 508 length of about 0.1at about 5 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.6 with a first segment 506 length ofabout 0.1 at about 2 degrees, a second segment 508 length of about 0.1at about 6 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.65 with a first segment 506 lengthof about 0.09 at about 2 degrees, a second segment 508 length of about0.09 at about 3 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.65 with a first segment 506 lengthof about 0.09 at about 0 degrees, a second segment 508 length of about0.09 at about 6 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.65 with a first segment 506 lengthof about 0.09 at about 3 degrees, a second segment 508 length of about0.09 at about 6 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.7 with a first segment 506 length ofabout 0.1 at about 0 degrees, a second segment 508 length of about 0.1at about 3 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.7 with a first segment 506 length ofabout 0.1 at about 3 degrees, a second segment 508 length of about 0.1at about 3 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.7 with a first segment 506 length ofabout 0.1 at about 0 degrees, a second segment 508 length of about 0.1at about 6 degrees with a transition segment 512 having a radius ofabout 0.14. In combination, the primer insert 32 may have a height fromtop surface 36 to tip 44 of about 0.7 with a first segment 506 length ofabout 0.1 at about 2 degrees, a second segment 508 length of about 0.1at about 6 degrees with a transition segment 512 having a radius ofabout 0.14.

In combination, the primer insert 32 may have a height from top surface36 to tip 44 of about 0.644 with a first segment 506 length of about0.075 at about 0 degrees, a second segment 508 length of about 0.116 atabout 3 degrees with a transition segment 512 having a radius of about0.14. In combination, the primer insert 32 may have a height from topsurface 36 to tip 44 of about 0.644 with a first segment 506 length ofabout 0.075 at about 3 degrees, a second segment 508 length of about0.116 at about 3 degrees with a transition segment 512 having a radiusof about 0.14. In combination, the primer insert 32 may have a heightfrom top surface 36 to tip 44 of about 0.644 with a first segment 506length of about 0.075 at about 0 degrees, a second segment 508 length ofabout 0.116 at about 6 degrees with a transition segment 512 having aradius of about 0.14. In combination, the primer insert 32 may have aheight from top surface 36 to tip 44 of about 0.644 with a first segment506 length of about 0.075 at about 3 degrees, a second segment 508length of about 0.116 at about 6 degrees with a transition segment 512having a radius of about 0.14. In combination, the primer insert 32 mayhave a height from top surface 36 to tip 44 of about 0.6 with a firstsegment 506 length of about 0.08 at about 0 degrees, a second segment508 length of about 0.12 at about 3 degrees with a transition segment512 having a radius of about 0.14. In combination, the primer insert 32may have a height from top surface 36 to tip 44 of about 0.6 with afirst segment 506 length of about 0.08 at about 3 degrees, a secondsegment 508 length of about 0.12 at about 3 degrees with a transitionsegment 512 having a radius of about 0.14. In combination, the primerinsert 32 may have a height from top surface 36 to tip 44 of about 0.6with a first segment 506 length of about 0.08 at about 0 degrees, asecond segment 508 length of about 0.12 at about 6 degrees with atransition segment 512 having a radius of about 0.14. In combination,the primer insert 32 may have a height from top surface 36 to tip 44 ofabout 0.6 with a first segment 506 length of about 0.08 at about 3degrees, a second segment 508 length of about 0.12 at about 6 degreeswith a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.65 with a first segment 506 length of about 0.08 atabout 0 degrees, a second segment 508 length of about 0.1 at about 3degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.65 with a first segment 506 length of about 0.08 atabout 2 degrees, a second segment 508 length of about 0.1 at about 3degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.65 with a first segment 506 length of about 0.08 atabout 0 degrees, a second segment 508 length of about 0.1 at about 6degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.65 with a first segment 506 length of about 0.08 atabout 3 degrees, a second segment 508 length of about 0.1 at about 6degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.7 with a first segment 506 length of about 0.075 atabout 0 degrees, a second segment 508 length of about 0.1 at about 3degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.7 with a first segment 506 length of about 0.075 atabout 2 degrees, a second segment 508 length of about 0.1 at about 3degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.7 with a first segment 506 length of about 0.075 atabout 0 degrees, a second segment 508 length of about 0.1 at about 6degrees with a transition segment 512 having a radius of about 0.14. Incombination, the primer insert 32 may have a height from top surface 36to tip 44 of about 0.7 with a first segment 506 length of about 0.075 atabout 3 degrees, a second segment 508 length of about 0.1 at about 6degrees with a transition segment 512 having a radius of about 0.14.

The primer insert 32 also includes a first outer segment 520 thatextends from the end 502 to a first outer point 522 to define a firstouter segment length and a first outer segment angle. The first outersegment 520 may be subdivide into multiple segments (e.g., 1, 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41,42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,60, 65, 70, 75, 80, 85, 90, 95 or more) with each having independentangles and provide the same function without departing from the scope ofthe instant invention. The first outer angle may be between −15 and 15degrees from perpendicular to the top surface 36. An outer transitionsegment 524 is formed between the first outer point 522 and a side wall526. The outer transition segment 524 may be one or more segment thatare individually a curve, radius, straight, free-formed or othersegments, e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34,35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52,53, 54, 55, 56, 57, 58, 59, 60, 65, 70, 75, 80, 85, 90, 95 or more totransition from the first outer segment 520 to the side wall 526.

FIG. 6 depicts a side, cross-sectional view of a portion of thepolymeric cartridge case displaying ribs according to one embodiment ofthe present invention. FIG. 6 depicts a portion of a polymer casinghaving a shortened insert, angled coupling elements and internal ribs.The primer insert 32 includes a coupling element 30 extending from abottom surface 34 that is opposite a top surface 36. Located in the topsurface 36 is a primer recess 38 that extends toward the bottom surface34. A primer flash aperture 40 is located in the primer recess 38 andextends through the bottom surface 34 into the powder chamber 14. Thecoupling end 22 extends the polymer over the coupling element 30 andthrough the primer flash aperture 40 to form an aperture coating 42 thatretains the passage from the top surface 36 through the bottom surface34 and into the powder chamber 14 while providing support and protectionabout the primer flash aperture 40. When contacted the middle bodycomponent 28 interlocks with the coupling element 30 that extends with ataper to a smaller diameter at the tip 44 and forms a physical interlockbetween the primer insert 32 and middle body component 28. The middlebody component 28 extends through the flash aperture 40 into the primerrecess 38 into a primer recess groove 39 located around the flashaperture 40 in the primer recess 38. Coupling end 22 is shown as afemale element, but may also be configured as a male element inalternate embodiments of the invention. A diffuser maybe placed in theprimer recess against the primer recess groove 39 and the primer (notshown). The substantially cylindrical opposite end 20 or anywhere withinthe powder chamber 14 may include one or more ribs 48 on the surface.The number of ribs 48 will depend on the specific application and desireof the manufacture but may include 1, 2, 3, 4, 5 6, 7, 8, 9, 10, or moreribs. In the counter bore, the polymer was having difficulty fillingthis area due to the fact that the polymer used has fillers in it, andneeded to be reblended during molding. One embodiment includes six ribs48 to create turbulence in the flow of the polymer, thus allowing thematerial to fill the counter bore. Another embodiment of the instantinvention is a shortened insert and angled coupling element 30 inside ofthe insert. In addition, raised portions of the polymer at the flashhole, lowered and angled the internal polymer wall to match the insertand lengthened the internal ribs.

FIG. 7 depicts a side, cross-sectional view of a polymeric cartridgecase having a diffuser according to one embodiment of the presentinvention. The diffuser 50 is a device that is used to divert theeffects of the primer off of the polymer and directing it to the flashhole. The affects being the impact from igniting the primer as far aspressure and heat. The ammunition cartridge 10 is shown with a polymercasing 12 having a powder/propellant chamber 14 with a projectileaperture 16 at one end and an overmolded primer insert 32 at the other.The polymeric nose 18 extending from projectile aperture 16 toward thenose joint 20 which are separated by a neck 26 and a shoulder 24. Thenose joint 20 may be configured in various designs that allow thejoining of the polymeric nose 18 to the middle body component 28. Forexample, the joint 20 may be a butt joint, a bevel lap splice joint, ahalf lap joint, a lap joint, a square joint, a single bevel joint,double bevel joint, single J joint, double J joint, single v joint,double v joint, single U joint, double U joint, flange joint, tee joint,flare joint, edge joint, rabbit joint, dado and any other joint. Inaddition, the joint type may be modified to allow a gap at regions inthe joint. For example, a dado joint may be formed where the fit is notsquare allowing gaps to form at the corner of the dado. Similarly, acompound joint may be used, e.g., rabbit joint transitioning to a buttjoint transitioning to a bevel joint (modified to have a gap in the fit)transitioning to a butt joint and ending in a lap joint or rabbit joint.In addition the angle of the joint need not be at 90 and 180 degrees.The joint angle may be at any angle from 0-180 degrees and may varyalong the joint. For instance the joint may start at a 0 degree move toa +45 degree angle transition to a −40 degree angle and conclude bytapering at a 10 degree angle. The polymeric nose 18 typically has awall thickness between about 0.003 and about 0.200 inches and preferablybetween about 0.005 and more preferably between about 0.150 inches about0.010 and about 0.050 inches. The middle body component 28 is formed bymolding a case joint 19 at one end and overmolding the primer insert 32at the other. A coupling element 30 extending from a bottom surface 34that is opposite a top surface 36. The middle body component 28overmolds the coupling element 30 of the insert 32. The coupling element30, as shown, is configured as a male element, however, all combinationsof male and female configurations are acceptable for coupling elements30. Located in the top surface 36 of the primer insert is a primerrecess 38 that extends toward the bottom surface 34. A primer flashaperture 40 is located in the primer recess 38 and extends through thebottom surface 34 into the interior of the middle body component 28 toform a powder chamber 14. The coupling end 22 extends the polymerthrough the primer flash aperture 40 to form an aperture coating 42while retaining a passage from the top surface 36 through the bottomsurface 34 and into the powder chamber 14 to provide support,communication and protection about the primer flash aperture 40. Themiddle body component 28 extends through the flash aperture 40 into theprimer recess 38 and into a primer recess groove 39. The middle bodycomponent 28 typically has a wall thickness between about 0.002 andabout 0.400 inches and between 0.003 and about 0.200 inches morepreferably between about 0.005 and more preferably between about 0.150inches about 0.010 and about 0.050 inches. The projectile aperture 16,the middle body 28 and the overmolded bottom surface 34 define theinterior of a powder/propellant chamber 14 in which the powder charge(not shown) is contained. The interior volume of powder/propellantchamber 14 may be varied to provide the desired volume ofpowder/propellant to achieve the desired goal, e.g., fps, pressure, etc.Any powder/propellant known to the skilled artisan can be used.Generally, either a particulate or consolidated propellant is used. Theprimer insert 32 also has a flange 46 and a primer recess 38 formedtherein for ease of insertion of the primer (not shown). The primerrecess 38 is sized to receive a primer (not shown) in an interferencefit during assembly. A diffuser 50 may be placed between the primer (notshown) and the bottom of the primer recess 38. The diffuser 50 includesa diffuser aperture 52 that aligns with the primer flash aperture 40.The diffuser 50 is a device that is used to divert the affects of theprimer (not shown) off of the polymer. The affects being the impact fromigniting the primer as far as pressure and heat to divert the energy ofthe primer off of the polymer and directing it to the flash hole. Thediffuser 50 may be of any diameter, thickness and material. A primerflash hole 40 communicates through the bottom surface 34 of primerinsert 32 into the powder chamber 14 so that upon detonation of theprimer (not shown), the powder in the powder chamber 14 will be ignited.The projectile (not shown) is held in place within the neck 26 atforward the projectile aperture 16 by an interference fit, mechanicalcrimping, adhesive, bonding welding, or etc. to increase the bullet pullforce.

FIG. 8 depicts a side, cross-sectional view of a portion of thepolymeric cartridge case having a diffuser according to one embodimentof the present invention. FIG. 8 shows a portion of a polymer casing 12showing a powder chamber 14 and the primer insert 32. The primer insert32 includes a coupling element 30 extending from a bottom surface 34that is opposite a top surface 36. Located in the top surface 36 is aprimer recess 38 that extends toward the bottom surface 34. A primerflash aperture 40 is located in the primer recess 38 and extends throughthe bottom surface 34 into the powder chamber 14. The coupling end 22extends the polymer over the coupling element 30 and through the primerflash aperture 40 to form an aperture coating 42 that retains thepassage from the top surface 36 through the bottom surface 34 and intothe powder chamber 14 while providing support and protection about theprimer flash aperture 40. When contacted the middle body component 28interlocks with the coupling element 30 that extends with a taper to asmaller diameter at the tip 44 and forms a physical interlock betweenthe primer insert 32 and middle body component 28. The middle bodycomponent 28 extends through the flash aperture 40 into the primerrecess 38 into a primer recess groove 39 located around the flashaperture 40 in the primer recess 38. Coupling end 22 is shown as afemale element, but may also be configured as a male element inalternate embodiments of the invention. A diffuser 50 maybe placed inthe primer recess against the primer recess groove 39 and the primer(not shown). The diffuser 50 includes a diffuser aperture 52 and adiffuser aperture extension 54 that aligns with the primer flashaperture 40. The diffuser 50 is a device that is used to divert theaffects of the primer (not shown) off of the polymer. The affects beingthe impact from igniting the primer as far as pressure and heat todivert the energy of the primer off of the polymer and directing it tothe flash hole. The diffuser 50 can be between 0.004 to 0.010 inches inthickness and made from half hard brass. For example, the diffuser 50can be between 0.005 inches thick for a 5.56 diffuser 50. The OD of thediffuser for a 5.56 or 223 case is 0.173 and the ID is 0.080. TheDiffuser could be made of any material that can withstand the energyfrom the ignition of the primer. This would include steel, stainless,cooper, aluminum or even an engineered resin that was injection moldedor stamped. The Diffuser can be produce in T shape by drawing thematerial with a stamping and draw die. In the T Diffuser the center ringcan be 0.005 to 0.010 tall and the OD is 0.090 and the ID 0.080.

FIGS. 9a-9h depict different embodiment of the diffuser of the presentinvention.

The polymeric and composite casing components may be injection molded.Polymeric materials for the bullet-end and middle body components musthave propellant compatibility and resistance to gun cleaning solventsand grease, as well as resistance to chemical, biological andradiological agents. The polymeric materials must have a temperatureresistance higher than the cook-off temperature of the propellant,typically about 320° F. The polymeric materials must haveelongation-to-break values that to resist deformation under interiorballistic pressure as high as 60,000 psi in all environments(temperatures from about −65 to about 320° F. and humidity from 0 to100% RH). According to one embodiment, the middle body component iseither molded onto or snap-fit to the casing head-end component afterwhich the bullet-end component is snap-fit or interference fit to themiddle body component. The components may be formed from high-strengthpolymer, composite or ceramic.

Examples of suitable high strength polymers include composite polymermaterial including a tungsten metal powder, nylon 6/6, nylon 6, andglass fibers; and a specific gravity in a range of 3-10. The tungstenmetal powder may be 50%-96% of a weight of the bullet body. The polymermaterial also includes about 0.5-15%, preferably about 1-12%, and mostpreferably about 2-9% by weight, of nylon 6/6, about 0.5-15%, preferablyabout 1-12%, and most preferably about 2-9% by weight, of nylon 6, andabout 0.5-15%, preferably about 1-12%, and most preferably about 2-9% byweight, of glass fibers. It is most suitable that each of theseingredients be included in amounts less than 10% by weight. Thecartridge casing body may be made of a modified ZYTEL resin, availablefrom E.I. DuPont De Nemours Co., a modified 612 nylon resin, modified toincrease elastic response.

Examples of suitable polymers include polyurethane prepolymer,cellulose, fluoro-polymer, ethylene inter-polymer alloy elastomer,ethylene vinyl acetate, nylon, polyether imide, polyester elastomer,polyester sulfone, polyphenyl amide, polypropylene, polyvinylidenefluoride or thermoset polyurea elastomer, acrylics, homopolymers,acetates, copolymers, acrylonitrile-butadinen-styrene, thermoplasticfluoro polymers, inomers, polyamides, polyamide-imides, polyacrylates,polyatherketones, polyaryl-sulfones, polybenzimidazoles, polycarbonates,polybutylene, terephthalates, polyether imides, polyether sulfones,thermoplastic polyimides, thermoplastic polyurethanes, polyphenylenesulfides, polyethylene, polypropylene, polysulfones, polyvinylchlorides,styrene acrylonitriles, polystyrenes, polyphenylene, ether blends,styrene maleic anhydrides, polycarbonates, allyls, aminos, cyanates,epoxies, phenolics, unsaturated polyesters, bismaleimides,polyurethanes, silicones, vinylesters, or urethane hybrids. Examples ofsuitable polymers also include aliphatic or aromatic polyamide,polyeitherimide, polysulfone, polyphenylsulfone, poly-phenylene oxide,liquid crystalline polymer and polyketone. Examples of suitablecomposites include polymers such as polyphenylsulfone reinforced withbetween about 30 and about 70 wt %, and preferably up to about 65 wt %of one or more reinforcing materials selected from glass fiber, ceramicfiber, carbon fiber, mineral fillers, organo nanoclay, or carbonnanotube. Preferred reinforcing materials, such as choppedsurface-treated E-glass fibers provide flow characteristics at theabove-described loadings comparable to unfilled polymers to provide adesirable combination of strength and flow characteristics that permitthe molding of head-end components. Composite components can be formedby machining or injection molding. Finally, the cartridge case mustretain sufficient joint strength at cook-off temperatures. Morespecifically, polymers suitable for molding of the projectile-endcomponent have one or more of the following properties: Yield or tensilestrength at −65° F.>10,000 psi Elongation-to-break at −65° F.>15% Yieldor tensile strength at 73° F.>8,000 psi Elongation-to-break at 73°F.>50% Yield or tensile strength at 320° F.>4,000 psiElongation-to-break at 320° F.>80%. Polymers suitable for molding of themiddle-body component have one or more of the following properties:Yield or tensile strength at −65° F.>10,000 psi Yield or tensilestrength at 73° F.>8,000 psi Yield or tensile strength at 320° F.>4,000psi.

Commercially available polymers suitable for use in the presentinvention thus include polyphenylsulfones; copolymers ofpolyphenylsulfones with polyether-sulfones or polysulfones; copolymersand blends of polyphenylsulfones with polysiloxanes;poly(etherimide-siloxane); copolymers and blends of polyetherimides andpolysiloxanes, and blends of polyetherimides andpoly(etherimide-siloxane) copolymers; and the like. Particularlypreferred are polyphenylsulfones and their copolymers with poly-sulfonesor polysiloxane that have high tensile strength and elongation-to-breakto sustain the deformation under high interior ballistic pressure. Suchpolymers are commercially available, for example, RADEL R5800polyphenylesulfone from Solvay Advanced Polymers. The polymer can beformulated with up to about 10 wt % of one or more additives selectedfrom internal mold release agents, heat stabilizers, anti-static agents,colorants, impact modifiers and UV stabilizers.

The polymers of the present invention can also be used for conventionaltwo-piece metal-plastic hybrid cartridge case designs and conventionalshotgun shell designs. One example of such a design is an ammunitioncartridge with a one-piece substantially cylindrical polymeric cartridgecasing body with an open projectile-end and an end opposing theprojectile-end with a male or female coupling element; and a cylindricalmetal cartridge casing head-end component with an essentially closedbase end with a primer hole opposite an open end having a couplingelement that is a mate for the coupling element on the opposing end ofthe polymeric cartridge casing body joining the open end of the head-endcomponent to the opposing end of the polymeric cartridge casing body.The high polymer ductility permits the casing to resist breakage.

One embodiment includes a 2 cavity prototype mold having an upperportion and a base portion for a 5.56 case having a metal insertover-molded with a Nylon 6 (polymer) based material. In this embodimentthe polymer in the base includes a lip or flange to extract the casefrom the weapon. One 2-cavity prototype mold to produce the upperportion of the 5.56 case can be made using a stripper plate tool usingan Osco hot spur and two subgates per cavity. Another embodimentincludes a subsonic version, the difference from the standard and thesubsonic version is the walls are thicker thus requiring less powder.This will decrease the velocity of the bullet thus creating a subsonicround.

The extracting inserts is used to give the polymer case a tough enoughridge and groove for the weapons extractor to grab and pull the case outthe chamber of the gun. The extracting insert is made of 17-4 ss that ishardened to 42-45rc. The insert may be made of aluminum, brass, cooper,steel or even an engineered resin with enough tensile strength.

The insert is over molded in an injection molded process using a nanoclay particle filled Nylon material. The inserts can be machined orstamped. In addition, an engineered resin able to withstand the demandon the insert allows injection molded and/or even transfer molded.

One of ordinary skill in the art will know that many propellant typesand weights can be used to prepare workable ammunition and that suchloads may be determined by a careful trial including initial lowquantity loading of a given propellant and the well known stepwiseincreasing of a given propellant loading until a maximum acceptable loadis achieved. Extreme care and caution is advised in evaluating newloads. The propellants available have various burn rates and must becarefully chosen so that a safe load is devised.

The description of the preferred embodiments should be taken asillustrating, rather than as limiting, the present invention as definedby the claims. As will be readily appreciated, numerous combinations ofthe features set forth above can be utilized without departing from thepresent invention as set forth in the claims. Such variations are notregarded as a departure from the spirit and scope of the invention, andall such modifications are intended to be included within the scope ofthe following claims.

It is contemplated that any embodiment discussed in this specificationcan be implemented with respect to any method, kit, reagent, orcomposition of the invention, and vice versa. Furthermore, compositionsof the invention can be used to achieve methods of the invention.

It will be understood that particular embodiments described herein areshown by way of illustration and not as limitations of the invention.The principal features of this invention can be employed in variousembodiments without departing from the scope of the invention. Thoseskilled in the art will recognize, or be able to ascertain using no morethan routine experimentation, numerous equivalents to the specificprocedures described herein. Such equivalents are considered to bewithin the scope of this invention and are covered by the claims.

All publications and patent applications mentioned in the specificationare indicative of the level of skill of those skilled in the art towhich this invention pertains. All publications and patent applicationsare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

The use of the word “a” or “an” when used in conjunction with the term“comprising” in the claims and/or the specification may mean “one,” butit is also consistent with the meaning of “one or more,” “at least one,”and “one or more than one.” The use of the term “or” in the claims isused to mean “and/or” unless explicitly indicated to refer toalternatives only or the alternatives are mutually exclusive, althoughthe disclosure supports a definition that refers to only alternativesand “and/or.” Throughout this application, the term “about” is used toindicate that a value includes the inherent variation of error for thedevice, the method being employed to determine the value, or thevariation that exists among the study subjects.

As used in this specification and claim(s), the words “comprising” (andany form of comprising, such as “comprise” and “comprises”), “having”(and any form of having, such as “have” and “has”), “including” (and anyform of including, such as “includes” and “include”) or “containing”(and any form of containing, such as “contains” and “contain”) areinclusive or open-ended and do not exclude additional, unrecitedelements or method steps.

The term “or combinations thereof” as used herein refers to allpermutations and combinations of the listed items preceding the term.For example, “A, B, C, or combinations thereof” is intended to includeat least one of: A, B, C, AB, AC, BC, or ABC, and if order is importantin a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB.Continuing with this example, expressly included are combinations thatcontain repeats of one or more item or term, such as BB, AAA, MB, BBC,AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan willunderstand that typically there is no limit on the number of items orterms in any combination, unless otherwise apparent from the context.

All of the compositions and/or methods disclosed and claimed herein canbe made and executed without undue experimentation in light of thepresent disclosure. While the compositions and methods of this inventionhave been described in terms of preferred embodiments, it will beapparent to those of skill in the art that variations may be applied tothe compositions and/or methods and in the steps or in the sequence ofsteps of the method described herein without departing from the concept,spirit and scope of the invention. All such similar substitutes andmodifications apparent to those skilled in the art are deemed to bewithin the spirit, scope and concept of the invention as defined by theappended claims.

What is claimed is:
 1. A polymer ammunition cartridge comprising: aprimer insert for comprising a top surface; a bottom surface oppositethe top surface; a coupling element that extends from the bottomsurface, wherein the coupling element comprises an interior surface andan exterior surface, wherein the interior surface comprises: atransition region that transitions from the bottom surface to a secondsegment wherein the transition region has a radius of from 0.02 to 0.2;a first segment extending from the second segment and terminates at atip, wherein the first segment has a first segment distance from 0.02 to0.18 inches and the second segment has a second segment distance from0.02 to 0.18 inches, wherein the second segment has a second segmentangle from +3 to −3 degrees relative to the first segment angle and thefirst segment has a first segment angle from +6 to −6 degrees fromperpendicular to the top surface; a primer recess in the top surfacethat extends toward the bottom surface; a primer flash aperturepositioned in the primer recess through the bottom surface; and a flashaperture groove in the primer recess and positioned around the primerflash aperture and adapted to receive a polymer overmolding through theprimer flash aperture; a polymeric middle body comprising a polymericbody extending from a body coupling over at least a portion of theprimer insert, wherein the polymeric body is molded over the cylindricalcoupling element and into the primer flash hole aperture and into thegroove to form a primer flash hole; and a polymer nose comprising agenerally cylindrical neck having a projectile aperture at a first end;a shoulder that extends from the generally cylindrical neck; and a nosejunction in communication with the shoulder, wherein the nose junctionis mated to the body coupling.
 2. The polymer ammunition cartridge ofclaim 1, wherein the transition region comprises one or more straightsegments, one or more curved segments or a combination of one or morestraight segments and one or more curved segments.
 3. The polymerammunition cartridge of claim 1, wherein the first segment has a firstsegment distance is about 0.08 inches, the second segment has a secondsegment distance is about 0.08 inches and the transition region isconcave with a radius of about 0.04.
 4. The polymer ammunition cartridgeof claim 3, wherein the second segment has a second segment angle isabout 1 degree and the first segment has a first segment is about 3degrees.
 5. The polymer ammunition cartridge of claim 3, wherein thesecond segment has a second segment angle is about 3 degrees and thefirst segment has a first segment is about 0 degrees.
 6. The polymerammunition cartridge of claim 3, further comprising an insert heightthat extends from the top surface to the tip, wherein the insert heightis about 0.34 inches; about 0.36 inches; or about 0.38 inches.
 7. Thepolymer ammunition cartridge of claim 1, wherein the first segment has afirst segment distance is about 0.079 inches, the second segment has asecond segment distance is about 0.083 inches and the transition regionis concave with a radius of about 0.04.
 8. The polymer ammunitioncartridge of claim 9, wherein the second segment has a second segmentangle is about 1 degree and the first segment has a first segment isabout 3 degrees.
 9. The polymer ammunition cartridge of claim 9, whereinthe second segment has a second segment angle is about 3 degrees and thefirst segment has a first segment is about 0 degrees.
 10. The polymerammunition cartridge of claim 9, further comprising an insert heightthat extends from the top surface to the tip, wherein the insert heightis about 0.34 inches; is about 0.36 inches; or is about 0.38 inches. 11.The polymer ammunition cartridge of claim 1, wherein the first segmenthas a first segment distance is about 0.076 inches, the second segmenthas a second segment distance is about 0.086 inches and the transitionregion is concave with a radius of about 0.04.
 12. The polymerammunition cartridge of claim 15, wherein the second segment has asecond segment angle is about 1 degree and the first segment has a firstsegment is about 3 degrees.
 13. The polymer ammunition cartridge ofclaim 15, wherein the second segment has a second segment angle is about3 degrees and the first segment has a first segment is about 0 degrees.14. The polymer ammunition cartridge of claim 15, further comprising aninsert height that extends from the top surface to the tip, wherein theinsert height is about 0.36 inches or about 0.38 inches.
 15. The polymerammunition cartridge of claim 1, wherein the first segment has a firstsegment distance is about 0.082 inches, the second segment has a secondsegment distance is about 0.08 inches and the transition region isconcave with a radius of about 0.04.
 16. The polymer ammunitioncartridge of claim 1, wherein the polymer nose, the polymeric middlebody or both individually comprise a nylon polymer, polycarbonatepolymer, polybutylene polymer or a mixture thereof.
 17. The polymerammunition cartridge of claim 1, wherein the polymer nose, the polymericmiddle body or both individually comprise between about 10 and about 70wt % glass fiber fillers, mineral fillers, or mixtures thereof.
 18. Thepolymer ammunition cartridge of claim 1, further comprising an adhesivegroove positioned in the projectile aperture.
 19. The polymer ammunitioncartridge of claim 1, wherein the polymer nose, the polymeric middlebody or both individually comprise a polymers selected from the groupconsisting of polyurethane prepolymer, cellulose, fluoro-polymer,ethylene inter-polymer alloy elastomer, ethylene vinyl acetate, nylon,polyether imide, polyester elastomer, polyester sulfone, polyphenylamide, polypropylene, polyvinylidene fluoride or thermoset polyureaelastomer, acrylics, homopolymers, acetates, copolymers,acrylonitrile-butadinen-styrene, thermoplastic fluoro polymers, inomers,polyamides, polyamide-imides, polyacrylates, polyatherketones,polyaryl-sulfones, polybenzimidazoles, polycarbonates, polybutylene,terephthalates, polyether imides, polyether sulfones, thermoplasticpolyimides, thermoplastic polyurethanes, polyphenylene sulfides,polyethylene, polypropylene, polysulfones, polyvinylchlorides, styreneacrylonitriles, polystyrenes, polyphenylene, ether blends, styrenemaleic anhydrides, polycarbonates, allyls, aminos, cyanates, epoxies,phenolics, unsaturated polyesters, bismaleimides, polyurethanes,silicones, vinylesters, urethane hybrids, polyphenylsulfones, copolymersof polyphenylsulfones with polyethersulfones or polysulfones, copolymersof polyphenylsulfones with siloxanes, blends of polyphenylsulfones withpolysiloxanes, poly(etherimide-siloxane) copolymers, blends ofpolyetherimides and polysiloxanes, and blends of polyetherimides andpoly(etherimide-siloxane) copolymers.